Oil distillate cooler or condenser



Dec. 19, 1933. J. s. WALLIS 1,940,338

OIL DISTILLATE COOLER OR CONDENSER Filed on. 25. 1950 2 Sheets-Sheet 1A; ATTORNEY Dec. 19, 1933; .1. s. WALLIS OIL DISTILLATE COOLER ORCONDENSER Fild Oct. 25, 1930 2 Sheets-Sheet 2 ii 13 0 u! m. -M WVIlLWI'lr/ 7. O

dag I/g/jNTOR 46,; ATT-OR EY the tubes withcastings.

Patented Dec. 19, 1933 UNITED STATES PATENT OFFICE a 1,940,338 OILDISTILLATE COOLER 0R. CONDENSER,

v John Samuel Wallis, New York, N. Y. I Application October 25, 1930.Serial No. 491,183

'1 Claims. 01, 257-196) My invention relates to coolers or condensersfor cooling oil,that is hydrocarbon fluid, in oil distillation processesand the like. a h 7 Oil products leaving a fractionating tower or 6other oil treatment apparatus, pass through condensers or coolers orboth. Since condensers are coolers, such devices'wil1 in general hereinbe termed coolers. a,

So far as I am' aware, previously known comll) mercial coolers consistof pipe coils submerged in a water tank-There. are two objections tothis known type ofcooler; first, as respects space required; and,second, as respects heat transfer. The coils usually consist ofvertically disposed ,1 rows of horizontal tube portions connectedalternately at the ends by bends. The horizontal portions of these tubesare arranged about a foot apart. In acooler of this'known type,furthermore, the inside surface, which is contacted-by oil, isless areathan the outside surface, which is contacted by water. The specific heatof water is approximatelytwice that of oil, and the rate of heattransferflbetween metal and water isgreater by several times thantherate of heat transfer betweenmetm and'oil. "The heat transfer betweenthe oil and the'metal wall is consequently the limiting factor. V a

I propose to overcome theabove disadvantages and, to provide an improvedcooler by" replacing These castings have, preferably, smooth outsidevertical walls. Inter- Dally the castings contain ribs which serve, twopurposes. The ribs are arranged to form a pluralityof, horizontalpassages alternately conn'ected 38 at opposite ends'of the castings;Theflrlbs further appreciably increase the inside or oil contactsurfaces relative to the external or water contact surfaces,Variousfo'rms ofribs may beused, but each casting is preferably sodesigned that the 0 oil contact surface and thewater contact surface areininve'rse proportion, or at least substantially inverse proportion, tothe specific heat of the respective fluidsand preferably in inverseproportions to the rates ofheat transfer between the respective fluidsand the casting. Since the ribs are notqulte as eflicient as the sidewalls for the transmission of heat, I preferably provide an excess ofinternal surface above the ratio set forth. The vertical walls ofthecsides ofthe castings determine passages for the water betweenthem.Since a greater length of path of flow, by several times, can beincluded in a given vertical height of casting than in a pipe typecooler, a smaller number of vertically disposed members can be employed,and consequently the size of the water ing has side walls 16 which areparallel and ver- .tically disposed, a top wall 17, a bottom wall 18webs 24 extend between the sidewalls 16 and are of less'length than theinternal lengthof tank can be materially reduced; The reduction of thewater tank provides greater velocity in the water tank betweenthe'castings and in contact with the side walls thereof, which increasein velocity is an aid to heattransfer and helps to so improve theefliciency. I find that with the present invention the size of watertank for a given capacity can becut substantially in half. Furthermore,since a smaller member of vertically disposed memberscan be employed,the oil velocity will be increased as compared with the previously knowncoolers and thus the heat transfer from the oil is'also improved due toits velocity.

Myinvention is'illustrated on the accompanying drawings, forming a partof thisspecification and on whichd i Fig. 1 is an elevationalcross-sectional view of one'embodiment of the invention, taken on theline 1--l of Fig. 2;

Fig. 2 is atransverse cross section taken on the line 2-2 of Fig. 1; andV 1 Figs. 3 through 6'show difierent kinds of ribs for use in thecasting of Figs. 1 and 2.

' My improved cooler includes a water tank 10 having an inlet 11 and anoutlet 12. Within the watertank is a plurality of vertically disposed'oil contacting groupsof cooling sections 14. Each group, in theembodiment shown, includes two castings disposed one above the other.Each castyes andyend walls 19. The end walls 19 are parallel V andvertically disposed. The top and bottom walls 17 and 18 are parallel andhorizontally disposed.

At the top of each casting is an inlet 20 and at the ,90

bottom of each casting is an outlet 21, Spacing members 22m castintegral with the castings.

Each casting is an integral casting, thus eliminating substantially allconnections. Horizontal the casting. Alternate webs extend from oppositeend walls to substantially the other end wall respectively. Each webterminates short of one end wall by an amount substantially equal to thedistancebetween the webs. The webs thus form parallel horizontalpassages which are connected in series alternately at opposite ends ofthe castings.

In the embodiment shown, four groups of castings of two castings each,are arranged vertically in the water tank 10. The upper connections ofthe upper castings are connected to a common inlet header 26, towhich'the oil is supplied. The

lower ends of the lower casting are connected to 7110 a common outletheader 27, through which the oil is conducted to storage or other placedepending upon the process. I-beams 28 and saddles 29 or othersupporting means may be provided to support the castings. The oil flowsin parallel downwardly through the castings, the castings beingconnected in series as shown in the drawings. It will be seen that theexternal water-cooled surface of each casting is less than the internaloil contact surface due to the provision of the webs 24. As shown inFig. 2, the webs 24 are slightly wider than the vertical distancebetween the webs. The internal surface has an area which is somewhatgreater than twice the outside sur-' face. This, as above stated, isdone to compensate for the difference in specific heat and rate of heattransfer between oil and water. Tests have shown that webs do not give100% heat transmitting efliciency, but webs arranged as shown in thedrawing should give approximately efficiency for the flows encounteredin normal use for oil cooling. This factor should therefore be takeninto account in increasing the internal surface above that whichcorresponds to the inverse ratio of specific heatsand heat transferrates of the respective fluids. V

Holes and plugs indicated at 30 are provided opposite each web at thepoint where it is spaced from an end wall. Each hole affords access totwo horizontal passages, thus facilitating cleaning with a minimumnumber of plugs. The plug holes are useful in casting the section.

By casting the sections integral, I provide a minimum of bolted joints,there being bolted joints only where the castings are connected to themanifolds or headers and-where the castings are connected to each otherin such instances asa plurality of castings being used in each section.The use of a casting permits the horizontal oil passages to beimmediately adjacent each other and thus provide many more passages perunit height than with the old type of oil cooler. It is impossible tohave the horizontal portions of a pipe cooler adjacent to eachother onaccount of .the end bends or loops. My cooler ,provides this advantage,while at the same time givingv the advantage of a proper heat transferin accordance with the characteristics of the liquids. Since there areso many more horizontal passages, the watertank can be reducedrelativeto the size required for a pipe cooler, and consequently thevelocity of the water flowing upwardly and alongside the castings isgreater than the rate of new of water in a pipe cooler. Dead spacesbetween horizontal pipe portions are eliminated, the castings acting asbaflies to give positive flow.

Heat transfer increases with increased velocity, and therefore my cooleris improved in efficiency due to the faster flow of water caused by thede crease of tank. size, in turn caused by the use of castings.

The webs may be of various forms. Fig. 3 shows horizontal webs whereinthe webs are substantially as wide as the passages between the webs. Inthis arrangement the internal surface is approximately twice theexternal surface. Fig. 4 shows webs of angular form, the internalsurface extending obliquely to the side walls. This gives a greateramount of internal surface for a given width of casting.

Fig. 5 shows different forms of webs. To in crease the internal surface,I provide fins 16. It will beobvious that these fins may be employed inthe other forms of construction shown. In cases where internal parallelsurfaces are used,

I prefer to have the bottom surface smooth and the other surfaces ofirregular form. The reason for this is to prevent deposits on the bottomsurface.

Fig. 6 shows still another form of web in which the web is thinner atthe center than at the side walls.

It will be understood that the invention is not limited to the precisestructure described and illustrated. For example, the casting need notnecessarily be arranged vertically as shown.

What I claim is:

1. An integral casting for an oil cooler comprising parallel side walls,parallel end walls, parallel top and bottom walls, and internal websparallel to the top and bottom walls and extending alternately fromopposite end walls to substantially the other end wall respectively andproviding a plurality of parallel passages for flow of oil connected inseries, said passages having an internal surface of greater area thanexternal surface and said webs being thicker adjacent the side wallsthan at more central points.

2. A water cooled oil cooler comprisinga water tank having, an inlet andan outlet, a plu-, rality of V parallel-vertically disposed.oil-conducting cooling sections in said water tank, each sectionconsisting of a unitary casting having parallel side walls'and internalwebs, said webs extending alternately from opposite end walls of thecasting to substantially the other end wall respectively and providing apluralityof parallel horizontal passages for flow of oil connected inseries, said webs providing aninternal oil con- .tact surface greaterthan the external water contact surface, said webs being thickeradjacent the side walls than at more central, points, and meanscomprising inlet and outlet headers for connecting the sections inparalleL' 3. A water cooled oil cooler comprising'ja water tank havingan inlet and an outlet, aplurality of parallel vertically disposedoil-conducting cooling sections in said water tank, each sectionconsisting of a unitary casting having parallel side wallsand internalwebs, said webs extending alternately from opposite end walls of thecasting to substantially the other end wall respectively and providing aplurality of parallel horizontal passages for flow of oil connected inseries, said webs-providing an internal oil contact surface greater thanthe external Water contact surface, said webs having surfaces extendingobliquely to the side walls, andmeans comprising inlet and'outletheaders for connecting the sections in parallel.

4. A water cooled oil cooler comprising a water tank having an inlet andan outlet, a plurality of parallel vertically disposed oil conductingcooling sections in'said water tank, each section consisting of aunitary casting having parallel side walls and internal webs, saidwebsextending alternately from opposite end, walls of the casting tosubstantially the other end wall reparallel to the top and bottom wallsand extending alternately from opposite end walls to substantially theother end wall respectively and providing a plurality of parallelpassages for flow of oil connected in series, said passages having aninternal surface of greater area than external surface and said webshaving surfaces extend- 7. An oil cooler comprising in combination acasing adapted to receive a cooling medium, a plurality of castingsdisposed within said casing adapted to be surrounded by said coolingmedium, said castings having internally extended surfaces having agreater area than the external surfaces thereof, a part of saidinternally extended surfaces arranged to constrain the flow of theliquid within the castings in predetermined paths, another part of saidinternally extended surfaces adapted to provide an increased heatexchange surface, said last named surfaces being disposed to avoidresistance to the flow of a liquid thereover, inlet openings for saidcastings, outlet openings for said castings and respective manifoldscommunicating with said inlet and outlet. openings.

' JOHN SAMUEL WALLIS.

